Some security measures

[camus]

@camus

This is a good point and I now fix it by asking clear questions that I will also use to search on the link you sent.
How can I block devices from accessing the Internet at certain time of the day?
How can I create a set of websites that these devices can access at certain time of the day?
How can I use for example (https://github.com/StevenBlack/hosts) to subject certain devices, while other devices on the same network are not subjected to being blocked from accessing the sites on that host file?
How can I set up Openwrt to display a message on the user's browser when they attempt to visit a website they are not allowed, such as: "you are not allowed to visit this website....."?

Just to make things clear, these are the specific questions.